(www.slowtwitch.com) Our Sport's elite have subjected themselves to physical stresses in ways unequalled by any group of people in human history. How often have these athletes gone over the edge and into the abyss? How do you know when you've done too much? And how do you come back from it? Over the next several days we'll ask that question and do our best to answer it. We've spoken to many of the world's best triathletes. We'll share their experiences, and their words of wisdom for you.

The period of 1989 to 94 were what Paul Huddle calls the Psychotic Years. Huddle saw it all firsthand, both in his own quest to become a top-caliber Ironman racer and in watching his longtime girlfriend Paula Newby-Fraser compete. "My first exposure to somebody who could really take it to the next level was Scott Molina. He redefined training for all of us. He set the tone for what a long-distance racer can be."

Molinas incredible work habits would be the first of three influences leading many of the top ultra-athletes to a new training and racing levelone that would allow men and women to break eight and nine hours respectively and perhaps go a bit past peak strength and fitness and into deep, endemic exhaustion.

The second such influence was the coming of the "Saxon horde"the migration of the German snowbirds to San Diego for the winter months. "They took it up another level," Huddle says. "They did amazing amounts of miles. We learned a lot from them." But the Germans just set the tone for what the next few years would be like as far as training was concerned.

What really ushered in the Psychotic Years, what pushed many of these athletes over the edge, was the Ironman World Series. Huddle remembers it this way: "Everyone thought this was great. It was the natural evolution. Kind of like the USTS for Ironman racers. So we all started chasing around the world, doing five Ironmans a year in order to win the title."

Certainly it was big money. Erin Baker won the womens title the first year and pocketed $50,000 on top of the earnings at each race. JulieAnne White won the title for women in 1992, and although by then the money had dwindled to $20,000 it still was plenty of incentive for a long-distance racer. Scott Tinley and Ray Browning traded the title for several years, with each of them producing stellar performances at races like New Zealand and Canada. Both were usually fried to a crisp by the time Hawaii came around, but Tinley still had enough gas in the tank to push Mark Allen to the limit with a second-place finish in 1991.

On top of the Ironman World Series, new races were popping up. Hard races. Like Zofingen, generally considered by those who race it to be harder than any Ironman. And the Nice triathlon was still on the schedule. It was not at all unusual for an athlete to do Zofingen, then race Nice a month later, then Germany a month after that. In 1992 JulieAnne White (my wife) raced Ironman New Zealand in March, Zofingen in May, then the Marseilles triathlon two weeks later followed by Nice two weeks after that. She raced Ironman Germany in July, Ironman Canada in August and, finally, six weeks later, Hawaii. A similar schedule ensued in 1993.Newby-Fraser also raced a heavy schedule in 1992, including a three-race triple that seems incomprehensible. Two weeks after the Nice Triathlon, she raced Ironman Japan, followed bytwo weeks laterthe German Ironman. Thats three ultras and three wins in a four-week span. When asked whether racing such a schedule had any lasting negative effects, Huddle maintains that, "the 1992 schedule was no problem for Paula. It was difficult, but she was fit and she got through it all fine. It was the 95 season that was difficult. But it wasnt the Hawaii race and it wasnt the meltdown at the end of that race. It was the training. She was tired of people taking for granted that she would win Hawaii, that she was expected to win. She wanted to really stick a top mens time out there, an 8:45 or so. So she did the kind of training a top man would do. She rode the 150-mile rides with Mark Allen, glued to his rear wheel. That was where she went overboard. Thats when she found the point of maximum output, and went past it."

What happens when an athlete goes too far, and how does he or she know when that has happened? Scott Molina has explored this as much as any athlete, both from firsthand experience as a pioneer in doing extraordinary amounts of quality training and racing, and in the self-examination of what that does to a person.

"I do believe there is enough accurate, reliable information out there to give people the necessary tools to decide whether they are doing too much," he says. "In 1987 I went to a clinic in Dallas where Peter Snell worked to be tested for overtraining. At the time it was a pretty vague term, but they had some concrete theories already that seem to be holding up today. They tested for hormonal levelsfree testosterone, cortisol, and muscle breakdown enzymesand combined that with resting heart rate and other subjective feelings: tiredness, irritability, etc. And of course I was a mess, which I knew, but didn't know how to correct myself. At the time they suggested a long time off, at least six weeks. This would have been my first break in 13 years, so I was a bit reluctant. But I took their advice and went on to have two good years in 88 and 89.

"The thing is, I knew I was in trouble because I was doing a ton of racing and training but couldn't go as fast as I should according to objective measures like track workouts and swim sessions that I've done hundreds of times. And I think most people who nuke themselves know it at the time, but because of their motivation to excel don't allow themselves to stop. And this is where I think triathlon is a bit different than other sports. We do seem to attract a higher percentage of compulsive/addictive types, so a higher percentage of us are likely to nuke ourselves. Only after coaching people for the last five years have I come to realize that many people who seek my advice do so because others have told them to do less, or take time off, but they won't. So they come to me to try and get the secret of how I did so much. Some of these folks just go from coach to coach, or doctor to doctor, hoping to find out how they can do and have it all, when the reality is that they can't.

"I do think that some athletes who did get a very early start in endurance trainingespecially swimmersseem to be able to cope with more as they reach adulthood. The others that seem to be able to handle more are those who do the highest percentage of their training at the low end of the aerobic scale. It seems it is the really hard stuff that tips the balance very quickly."

HEART TIRED

"The only guys I ever knew whod get heart-tired were the Germans. Nobody would do the amount of work they did," says longtime American pro Mark Montgomery, probably the first American to train regularly with such early German stars as Jurgen Zack, Wolfgang Dittrich and Jochen Basting. Montgomery was talking about a little-known maladya type of overtraining in which the heart is unable to beat at a rate high enough to do the work required.

"The Germans would do so much work, their legs were so strong, they were so fitthey were the only ones who could outwork their hearts," Mongomery says. "Theyd eventually get to a point where they couldnt get their heart rates up any more. Whenever that happened theyd train really easyeverything was below 110 beats per minute, and it might take them three weeks before their hearts came back. They would always just keep their work down [until] they recovered."

Most recreational athletes are more used to the notion that an elevated heart rate is the sign of overtraining, specifically during rest, and theyre right in their thinking. Fewer athletes are aware of, or ever experience, a heart that cannot beat fast enough. But professional triathletes are very aware of this phenomenon, especially those who engage in Ironman-style training and racing.

"There are days that I just can't get my HR to the zone I want it to be in," says Ironman and World Champion Karen Smyers. "This is a sign of not being recovered, and I reschedule the hard workout planned for that day. If you recognize it early, you can usually recover in a day or two. If you have pushed through it for a long time, you may need a much longer time to pull yourself out of the slump." Every triathlete who has done the big miles can relate to a time when the heart for some reason wont beat fast enough under load. What is in question is exactly why this happens and what the physiological mechanism behind it might be.

Dr. Edgar Fenzl is an avid triathlete. Hes also one of the most respected clinical researchers in Germany. He knows all the German athletes and many of the Americans. And he maintains that the heart doesnt get tired. "The heart is an amazing thing," he says. "You can do anything to your body you wantyou can exhaust every muscle you have, you can work yourself even to the point of passing out, but your heart will keep beating."

Fenzl is like every doctor interviewed for this article. There is no basis in theory, nor any reported studies, in which the conclusion can be drawn that the heart gets tired. Yet there is not one top Ironman-distance pro who cannot relate to the experience. That is not to say that Fenzl and the other doctors do not recognize the symptom; they simply believe it is a metabolic or electrophysiological problem. The heart has run out of something. Perhaps there is a deficiency in ATPase or a certain electrolyte.

The problem is also one that is not always noticeable. "You wont know youre heart-tired without a heart rate monitor," Montgomery says. "You feel OK, more or less, its just that youre out there doing an amount of work that should have you up to 150 beats, but your heart is only at 125. Your heart rate monitor is the only way youll know it."

While triathletes are the most likely to get heart-tired, long-distance cyclists can relate to the experience as well. "I was doing RAAM Relay one year," says Pete Pennsyres, winner of the Race Across America and holder of several long-distance records. "Every day I felt fine, but I had my heart rate monitor on and I found that I couldnt get my heart rate up to the level sustained the previous day."

Perhaps it is a lack of something needed that creates an environment in which the heart cannot beat at its regular tempo, or perhaps triathletes engage in so much more aerobic work that the heart finally reaches the limit of its incredible endurance. Either way, Scott Tinley sees it this way: "Bottom-line is that we are living lab rats who are working without a net. We [triathletes] are peerless, without precedent and subject to long-term maladies about which nobody knows. The body is an amazing piece of machinery. I am afraid a few of us may have found the limits of long-term endurance training. This is an area that warrants further study. I did quite a bit of research in this area and basically found little if anything specific to LONG-term overtraining.

"You can get away from it for awhile," Tinley says. "Two to four years, depending. But after a while it catches up. The warning signs are subtle, varied, and easily masked by an athletes determination. The interest in Ironman distances, and the money and sponsorship, are the carrots that drive those who have the basic tools to be competitive." But Tinley also agrees with Scott Molina that, "It is underlying obsessive/compulsive behavior that fuels the fires. The damage that can be done varies on the individual. Everybody has a breaking point. Mine was the neuro-endocrine system."

Whatever causes the heart to slow during exercise is reversible. Longtime pro Ironman racer and current coach and clinician Ray Browning says that perhaps the heart is protecting itself. "Most athletes are aware that a sign of overtraining is an elevated heart rate at rest, and they project that notion into the belief that it will be elevated during training as well. But thats untrue. I dont know the mechanisms behind the dissociation between heart rate and perceived effort, and when I talk about that phenomenon peoples eyes glaze over. But maybe it is the bodys way of protecting itself from damage." Browning wonders whether there is only a finite amount of hard work available to all of us. If so, maybe this is the bodys way of protecting us so that we can live to fight, or play, another day.

Paul Huddle remembers the great Ironman racing days when, after youve given your heart and body all the rest it needs, it is able to beat 10 beats faster than in training. Most of us are used to the idea of protecting against a higher than target heart rate. While a low heart rate at rest is quite desirable, the hearts ability to beat at its normal high rate is a sign of its health as well.

MEASURES

"The best measures of overtraining are still the ones you can perform at home," says Orange County-based physician Herman Falsetti, who has worked with many of the top pro triathletes, runners and cyclists who live in and pass through Southern California. "Irritability, the disinclination to eat, inability to sleep, and high resting heart rate are good indicators that youve done too much and need a rest."

But for those who fear theyve done more damage than a few days off will cure there are other, more quantitative and much more expensive measures. The one most in vogue for the past several years is testing ones blood cortisol level, specifically the "cortisol response." Cortisol is a corticosteriod naturally produced by the adrenal cortex. When you hear somebody say of a particular athlete, "His adrenals are shot," this term is not meant to apply to the ability to produce epinephrine (adrenaline), which is in any case produced by the adrenal medulla, not the adrenal cortex. Rather, the utterer of such a statement is referring, whether he knows it or not, to the ability of the body to properly produce and regulate cortisol.

A normally functioning person will have a certain amount of cortisol running around in his or her body at any time. During exercise the level goes up. After a brisk one-hour run, your blood cortisol level might be two to three times its resting level. But a severely overtrained person becomes a cortisol "secreter," meaning he is in a constant state of cortisol production that might be double what his normal resting output might be. When such a person exercises, his cortisol level does not go up as it should but stays roughly the same.Cortisol is responsible for a lot of necessary metabolic functions, only one of which is as a facilitator of gluconeogenesisa fancy word for what the liver does when it manufactures glucose, the gasoline for your bodys engine, out of proteins and fats. Some believe that a persons inability to further elevate cortisol levels during exercise is only half the problem; the already-elevated levels at rest are just as problematic. Since it is a catabolic steriod (anabolic=building, catabolic=tearing down), the extra blood cortisol may, over a long period of time, be running around eating up things like muscles and organs. Indeed, one of its "good" catabolic functions during periods of stress is to free amino acids for use. Might a "bad" catabolic function, if one's cortisol levels are perpetually high, be the slow erosion of muscle tissue? There are conflicting opinions as to whether this is one of the negative potential side-effects of elevated blood cortisol.

Mark Sisson, architect of every meaningful drug-testing protocol in the sport of triathlon and president of the supplement company Primal Nutrition, also maintains that cortisol inhibits calcium uptake. He suspects that elevated cortisol production over a period of time is the culprit for some of the bone-density and stress-fracture problems some athletes might suffer. "I think sometimes people take supplements hoping that they will fix a calcium deficiency, but when its their overtraining that is causing a calcium uptake problem, that's a problem supplements wont fix," he says.

Scott Tinley had cortisol response testing performed several years ago at Baylor University. "My cortisol was 13 at rest. I did a treadmill test and at work it went up to 13 and a half." He got tested again at the Olympic Training Center at Colorado Springs, and at exercise his cortisol level actually went down. "It was the first time theyd ever seen anything like that!"

Tinley is well-known inside pro triathlon circles as a "trainer." He rides and runs because he loves it, not because it is his job. But hes cut way down in recent years. He knows he probably ought to just take a year or two totally off, but thats a sacrifice hes unwilling to make. So, instead, hes keeping a careful watch on his work output and is slowly coming out of the hole into which he dug himself during two decades of constant training and several ultradistance races per year.

Some dont believe the malfunctioning entity is the adrenal gland, but that the problem is in the brain. The adrenal cortex does not act on its own. It secretes cortisol when prompted by adrenocorticotropic hormone, or ACTH. This is generated by the pituitary gland, and some believe that the problem lies solely in the brain, specifically in the hypothalmic-pituitary axis, or HPA. If you hear someone saying the adrenal-response problem may be a neurologicalas opposed to a glandularone, they are referring to the possibility that something went haywire up in the brain and that the problem is therefore further upstream: It's the brain's inability to sufficiently regulate production of ACTH.

Another measure of overtraining is ones level of testosterone, and athletes whove had their cortisol response tested usually will go one further and spring for a testosterone test as well. Testosterone becomes elevated during training in the same way cortisol does, so this test includes a test at rest and again after work. Some of these tests are done on a treadmill or bicycle ergometer and include blood samples taken as often as every 30 seconds.In an overtrained person testosterone does not become chronically elevated at rest, as does cortisol. Therefore, some think this is one of the harmful aspects of a hyper-overtrained statethe cortisol-testosterone balance is not maintained, and the catabolic effects of cortisol are not counteracted by the anabolic properties of testosterone.

But thats not the end of it. Some feel that the best measure is ones level of adrenaline and noradrenaline, and that levels of noradrenaline greater than 300 picograms per millileter after recovery from training suggest a person is overtrained. Another oft-mentioned measure is ones plasma glutamine levels. Glutamine is the first and most prevalent amino acid seen running around the bloodstream. This is because glutamine is essential for many homeostatic functionsand when the body is placed under stress, glutamine plasma levels rise, accompanied by a corresponding fall during recovery. If the body isnt allowed to recover sufficiently, glutamine levels never reach normalcyin other words, the levels stay low. Therefore, it is surmised that lower than normal levels of plasma glutamine could be a good indicator of overtraining.If you suspect you are overtrained and youve tried all the tests above and find them inconclusive, I might suggest further testing of your creatine kinase and serum ferritin. Have your doctor take a look under the hood and poke around your adrenal gland, perhaps through a camera inserted into your belly button. You might also consider having your mitochondria looked at under a microscope. All of this has been done by athletes whose names youd recognize. But if your performances are sub-par, if you cant sleep, cant eat, if youre irritable or depressed, you are probably overtrained and you dont need a blood test to tell you. Neither do you need a doctor to tell you the cure.

EPILOGUE

Most of you will never face the prospect of climbing out of a big hole such as those some pro triathletes have dug for themselves. But you might find yourself in transitory periods of overtraining, and when you do it might be because of too much "high quality" work. Roch Frey, coach of Heather Fuhr, Peter Reid, and others, says, " The body can only handle three hard workouts a week, and this is what most single sport athletes do at a maximum. Your internal system does not distinguish between an anaerobic swim, bike or run workout, but knows that the system is being overloaded and stressed regardless of what sport is being performed. Try telling most triathletes to only do one harder swim, bike and run weekly and most will laugh at you, except for a few: Heather and Peter follow this rule most of the time. This is one key to long term training that I think will save triathletes from sickness, and increase their longevity in the sport. Again, this is just my theory. I see so many triathletes hammering EVERY session."

But there are athletes, usually age-groupers, who hammer every session and do very well. These athletes have limitations, though. They are usually unable to race well at anything longer than a short-distance race. They will have more soft tissue injuries through their careers. There will also always be the question of whether they could have been better if they'd occasionally done longer miles.

Those who seem to be in greatest danger of overtraining are those who do embrace the notion of longer mileage for certain periods of time during their season, but do not heed the warnings about too many high heart rate sessions per week.

It seems easy to avoid overtraining by adhering to a few easy ground rules. But that's not much consolation to those who do triathlon at the highest levels and have spilled over into overtraining. Tinley laments: "The very aspects of your personality that lead you into overtrainingand keep you from getting out of itare those assets which got you to the top in the first place. My drive, discipline and work ethic make me react badly to the idea of disuse and atrophy. Thats the thing thats tough about trying to be the best. The very things that get you to the top are the things youve got to keep an eye on."